1. Field of the Invention
This invention relates to sockets for chip carriers for semiconductor chips and to the method of making them.
2. Description of the Prior Art
Semiconductor chips such as integrated circuits are normally mounted on chip carriers as is well known in the prior art. These chip carriers include ceramic elements or other insulating material upon which the chips are mounted with lead frames extending from pads on the chips to the exterior of the chip carrier for interconnection with elements of the outside world such as, for example, printed circuit boards. The prior art chip carriers have functioned very satisfactorily for their intended purpose in the past. However, the speed of operation of the circuits has increased and continues to increase. Since the chip carriers themselves are normally formed of ceramic and the like which are good dielectric materials, the semiconductor packages have built in capacitance and self-inductance in the leads required for the bonding pads on the chips to the external world. These capacitances and inductances are a function of frequency and increase as the speed of operation increases. The increase in system inductance and capacitance decreases the speed at which the circuits are capable of operating. These capacitances and inductances also appear in the sockets which connect the packages to printed circuit boards and the like. It is desirable to increase the operating speed of electronic components and, for this reason, it is necessary to decrease the built-in capacitance and self-inductance in the semiconductor chip package as well as in the sockets therefor.
It is known that, the longer the leads, the greater will be the built in capacitance and self-inductance. It is therefore the desire to provide a socket for an integrated circuit package with extended leads that has minimum inductive and capacitive properties when making connection to a separable device.